The present invention generally relates to the field of inhalers for delivering a plurality of droplets of medicament or other appropriate fluids to an individual, typically during inhalation.
Many types of medicaments or other types of fluids are delivered by inhalation for treating/addressing various types of conditions. Three general types of inhalers may be used for this type of xe2x80x9crespiratory therapy.xe2x80x9d Metered dose inhalers (xe2x80x9cMDIsxe2x80x9d) are relatively small, portable units which have a medicament disposed within a container of a pressurized gas or propellant (e.g., a mixture of medicament and propellant). The patient typically pushes down on this container to direct a xe2x80x9cburstxe2x80x9d of a mixture of propellant and medicament into the patient""s mouth during inhalation, with the propellant xe2x80x9cburstxe2x80x9d being provided by the pressure within the container. A fixed number of doses are available in a given MDI. What all the medicament has been dispensed from the container, typically the MDI or at least the container of medicament/propellant is discarded.
Another categorical type of inhaler is a nebulizer. These types of inhalers are not as portable as an MDI, and are more commonly used in a clinic or hospital setting. Generally, a nebulizer houses an appropriate medicament in liquid form. Gas from an external source is directed through an appropriate line under pressure and into the nebulizer to aerosolize the medicament for transport to the patient for delivery by inhalation. At the end of the treatment or upon the consumption of all of the liquid medicament in the nebulizer, and typically after a sterilization procedure, additional liquid medicament may be poured into the nebulizer for subsequent treatments.
The third general type of inhaler has a degree of portability which is similar to that of the MDI, but which uses sources other than an external supply of pressurized gas to generate droplets of the desired medicament. Some inhalers of this type use a small xe2x80x9con-boardxe2x80x9d source of pressurized gas to aerosolize a liquid medicament. Other inhalers use piezoelectric crystals and the like to aerosolize a liquid medicament in some manner. U.S. Pat. No. 5,894,841 to Voges, entitled xe2x80x9cDispenser,xe2x80x9d discloses another inhaler of this general categorical type, but which uses a xe2x80x9cdroplet on demandxe2x80x9d ejection device to generate droplets of medicament in the desired manner (e.g., a piezoelectric device of the kind used in ink jet printing or a thermal xe2x80x9cbubble jetxe2x80x9d device of the kind used in inkjet printing). The cartridge of medicament in the inhaler from U.S. Pat. No. 5,894,841 may be replaced after its medicament has been consumed or spent.
The present invention generally relates to enhancing one or more aspects associated with the delivery of medicament or other appropriate fluids/substances in typically the form of a plurality of droplets/particles for inhalation by a user of an inhaler (hereafter xe2x80x9cmedicamentxe2x80x9d).
A first aspect of the present invention is generally directed to an inhaler which includes an inhaler housing. At least one airflow passageway is interconnected with the inhaler housing. One or more portions of the airflow passageway(s) may extend beyond the inhaler housing, while other portions thereof may extend through the inhaler housing. In any case, there is at least one air inlet port for drawing air into the airflow passageway(s) utilized by the inhaler. Medicament is directed into this airflow passageway(s) by a droplet ejection cartridge. This droplet ejection cartridge includes a medicament reservoir, a plurality of droplet ejection orifices, and at least one droplet ejection actuator. Medicament from the reservoir is made available for ejection out through one or more of the droplet ejection orifices by activation of the droplet ejection actuator(s). In one embodiment there is a separately operable droplet ejection actuator for each droplet ejection orifice such that droplets of medicament may be directed out of the desired droplet ejection orifice(s). In any case, droplets of medicament which are entrained in the airflow through the airflow passageway(s) are directed into a mouthpiece when the same is appropriately interconnected with the airflow passageway(s). Therefore, a user simply positions his/her mouth about the mouthpiece and inhales for respiratory delivery of medicament by the inhaler.
The droplet ejection cartridge of the subject first aspect is removably disposed within a droplet ejection cartridge housing. In this regard, the droplet ejection cartridge housing includes a second droplet ejection cartridge aperture into which the droplet ejection cartridge may be positioned for support by the droplet ejection cartridge housing. Desirably, the second droplet ejection cartridge aperture of the droplet ejection cartridge housing is aligned with a first droplet ejection cartridge aperture which is formed in the inhaler housing. Therefore, the droplet ejection cartridge may be both loaded into and removed from the second droplet ejection cartridge aperture of the droplet ejection cartridge housing by passage through the first droplet ejection cartridge aperture of the inhaler housing. The droplet ejection cartridge housing also includes a droplet ejection aperture through which droplets are directed by the plurality of droplet ejection orifices at the desired time.
Various refinements exist of the features noted in relation to the subject first aspect of the present invention. Further features may also be incorporated in the subject first aspect of the present invention as well. These refinements and additional features may exist individually or in any combination. For instance, an appropriately configured cover may be provided for the first droplet ejection cartridge aperture formed in the inhaler housing and through which the droplet ejection cartridge may be directed for loading/unloading of the same from the droplet ejection cartridge housing. This cover may be movably interconnected with the inhaler housing, such as by a slide interface, a hinged interconnection, or the like. This particular cover may also be totally removable from the inhaler housing and may detachably interface with the inhaler housing (e.g., via a the snaplock type interconnect).
The inhaler of the subject first aspect of the present invention may also include an airflow conduit assembly which is interconnected with the inhaler housing. Each airflow passageway utilized by the inhaler of the subject first aspect may be directed through this airflow conduit assembly. Fluid interconnection between this airflow conduit assembly and the mouthpiece may be provided by engaging an inlet end of the mouthpiece on an outlet end of the airflow conduit assembly.
The droplet ejection cartridge housing may be disposed within the above-noted airflow conduit assembly and retained therein such that the droplet ejection cartridge housing and interior of the airflow conduit assembly are maintained in spaced relation so as to define at least part of the noted airflow passageway(s). One way in which this may be affected is by providing a pair of spaced apart partitions of sorts which extend between the interior surface of the airflow conduit assembly and the droplet ejection cartridge housing such that airflow is directed therebetween. In one embodiment, the droplet ejection cartridge housing includes first and second sides which are disposed opposite of each other, and further includes third and fourth sides which are disposed opposite of each other. One pair of the above-noted partitions may extend between the interior surface of the airflow conduit assembly and the first side of the droplet ejection cartridge housing to define one airflow passageway around the droplet ejection cartridge housing. Another pair of the above-noted partitions may extend between the interior surface of the airflow conduit assembly and the second side of the droplet ejection cartridge housing to define another airflow passageway around the droplet ejection cartridge housing. In one embodiment there is no airflow passageway between the interior of the airflow conduit assembly and either the third or fourth sides of the droplet ejection cartridge housing. Therefore, this then allows for a first airflow passageway section to be directed toward the droplet ejection cartridge housing, and then to effectively xe2x80x9csplitxe2x80x9d the same so as to flow around the droplet ejection cartridge housing on only two of the opposing sides of the droplet ejection cartridge housing.
The above-noted airflow conduit assembly may include both a plenum and an airflow conduit. One end of the airflow conduit could interface with the plenum, while its opposite end could interface with the mouthpiece. The first inlet port may be on the plenum. The size of this first inlet port may be adjustable, such as by including a cover or the like which is movably interconnected with the inhaler housing. Modification of the size of the first inlet port by moving the cover relative to the inhaler housing in turn modifies the inhalation resistance provided by the inhaler of the subject first aspect (e.g., for user preference and/or comfort). The first inlet port also may be offset in relation to the end of the airflow conduit which interfaces with the plenum. That is, the first inlet port on the plenum and the airflow conduit may be out of alignment such that air will not flow through the first inlet port on the plenum, through the plenum, and to the airflow conduit along a linear path. The plenum may be utilized to reduce the turbulence of air drawn therein prior to directing the same through the airflow conduit for injection of medicament droplets therein. Consider the case where the airflow conduit extends at least generally along a reference axis between its pair of opposing ends. In one embodiment, an area which is occupied by the plenum within a reference plane which is perpendicular to the reference axis along which the airflow conduit extends, is greater than an area occupied by the xe2x80x9cplenum endxe2x80x9d of the airflow conduit within a reference plane which is also perpendicular to the reference axis along which the airflow conduit extends.
Various portions of the airflow conduit assembly may be sized/contoured to facilitate the flow of air therethrough in a desired manner, as well as to provide a mechanism for the estimation of the rate of airflow through the conduit, all in relation to the subject first aspect of the present invention. Consider the case where the airflow conduit assembly includes an airflow conduit having 1U an inlet port and an outlet port which are longitudinally spaced relative to a reference axis along which the airflow conduit at least generally extends. Consider as well that there are at least three locations along this reference axis which have different diameters (i.e., the diameter of the airflow conduit may vary along its longitudinal extent). These three locations may be characterized as first, second, and third locations progressing in a direction corresponding with the airflow through the airflow conduit during inhalation (i.e., in a direction from the inlet port of the airflow conduit to the outlet port of the airflow conduit). The first location may actually define the first inlet port. The first, second, and third, which again represent different longitudinal positions along the noted airflow conduit, have first, second, and third diameters, respectively. The first diameter at the first longitudinal location is greater than the second diameter of the second longitudinal location. This change in diameter may be utilized to provide an increase in air velocity and consequently a reduction in pressure. The third diameter at the third longitudinal location is greater than the second diameter at the second longitudinal location. The droplet ejection cartridge housing may be disposed within a portion of the airflow conduit assembly which is defined by this third diameter such that the airflow through the airflow conduit may be directed xe2x80x9caroundxe2x80x9d the droplet ejection cartridge housing.
Further enhancements may be incorporated into the design of the inhaler of the subject first aspect in relation to the manner of ejecting medicament droplets into the airflow. In this regard, the droplet ejection cartridge housing may include a first end which projects at least generally toward the mouthpiece when the same is fluidly interconnected with the airflow passageway(s) associated with the inhaler. This first end of the droplet ejection cartridge may include a recess having the above-noted droplet ejection aperture formed therein. The droplet ejection cartridge may be oriented in the droplet ejection cartridge housing such that the plurality of droplet ejection orifices direct medicament droplets from the droplet ejection cartridge out through the droplet ejection aperture which is recessed on the first end of the droplet ejection cartridge housing. Recessing the droplet ejection discharge aperture in this manner is believed to introduce the medicament droplets into a zone having a minimal airflow therethrough. Vanes may be attached to the first end of the droplet ejection cartridge housing to further shield the ejected medicament droplets from the airflow which is passing the droplet ejection cartridge housing.
The mouthpiece of the subject first aspect of the present invention is at least fluidly interconnectable with the above-noted airflow passageway. Various features may be incorporated in the subject first aspect in relation to this mouthpiece. The length of the mouthpiece may be selected such that medicament that is ejected from the droplet ejection cartridge is traveling at least at substantially the same, and more preferably the same, velocity as the airflow prior to exiting an outlet end of the mouthpiece. In the case where the airflow passageway(s) is defined by an airflow conduit assembly, an inlet end of the mouthpiece may interface with the outlet end of the airflow conduit assembly. An outlet end of the mouthpiece, which is disposed opposite the inlet end of the mouthpiece, would then typically be inserted into the user""s mouth. In one embodiment, the inlet end of the mouthpiece has a circular cross-sectional profile, while the outlet end of the mouthpiece has an elliptical cross-sectional profile of a horizontal axis making it similar to the shape of the mouth of a user (e.g., a major axis that is at least substantially co-linear with the xe2x80x9clinexe2x80x9d between the user""s upper and lower lips when joined). Having an elliptical cross-sectional profile of the outlet end of the mouthpiece also allows the same to be orientated such that it is at least generally aligned with a perimeter of the plurality of droplet ejection orifices of the droplet ejection cartridge. to Different sizes may also be utilized for the inlet and outlet ends of the mouthpiece. An area of the opening defined by the inlet end of the mouthpiece may be larger than an area of the opening defined by the outlet for reducing the turbulence of the airflow entering the mouthpiece.
Another feature which may be utilized in relation to the mouthpiece of the subject first aspect is that it may be totally removable from the inhaler, and may interface or be interconnected with the inhaler at two different, spaced locations. When interconnected with the inhaler at a first location, the mouthpiece is fluidly interconnected with the airflow passageway(s) for purposes of delivering medicament droplets to a user of the inhaler. Disconnecting the mouthpiece from the airflow passageway(s) allows the mouthpiece to be moved to its second location on the inhaler, such as for storage purposes. In one embodiment the second location is a mouthpiece storage bay within the inhaler housing in which the mouthpiece may be positioned. The mouthpiece may be enclosed within the storage bay by including a mouthpiece storage bay cover which is at least partially detachably interconnectable with the inhaler housing for accessing the mouthpiece storage bay (e.g., using a slidable interconnection, using a hinge assembly, having the cover be totally removable from the inhaler housing). Removal of the fluid interconnection between the mouthpiece and airflow passageway(s) may expose the plurality of droplet ejection orifices to ambient conditions. It may be desirable to provide a droplet ejection orifice cover with a seal which may be disposed within the opening which remains after the mouthpiece is removed such that the seal may be disposed about the plurality of droplet ejection orifices. This droplet ejection orifice cover may be interconnected with the inhaler housing by a tether, although other ways may be utilized for storing the droplet ejection orifice cover when not in use.
A second aspect of the present invention is generally directed to an inhaler which includes an inhaler housing. At least one airflow passageway is interconnected with the inhaler housing. One or more portions of the airflow passageway(s) may extend beyond the inhaler housing, while other portions thereof may extend through the inhaler housing. In any case, there is at least one inlet port to the airflow passageway(s) utilized by the inhaler. Medicament from an appropriate container, which is interconnected with the inhaler housing, is directed into this airflow passageway(s) by a droplet ejection device. Medicament droplets are entrained within the airflow through the airflow passageway(s) and are directed into the mouth of a user of the inhaler through a mouthpiece which is at least fluidly interconnectable with the airflow passageway(s) or a first location on the inhaler. The mouthpiece may also be fluidly disconnected from the airflow passageway(s), totally removed from contact with the inhaler, and then interconnected with the inhaler at a second location which is spaced from the first location. When interconnected with the inhaler at the first location, the mouthpiece is fluidly interconnected with the airflow passageway(s) for purposes of delivering medicament droplets to a user of the inhaler. Separating the mouthpiece from the airflow passageway(s) allows the mouthpiece to be moved to its second location on the inhaler, such as for storage purposes. In one embodiment the second location is a mouthpiece storage bay within the inhaler housing in which the mouthpiece may be positioned. The mouthpiece may be enclosed within the storage bay by including a mouthpiece storage bay cover which is at least partially detachably interconnectable with the inhaler housing for accessing the mouthpiece storage bay (e.g., using a slidable interconnection, using a hinge assembly, having the cover be totally removable from the inhaler housing). Removal of the fluid interconnection between the mouthpiece and airflow passageway(s) may expose the plurality of droplet ejection orifices to ambient conditions. It may be desirable to provide a droplet ejection orifice cover with a seal which may be disposed within the opening which remains after the mouthpiece is removed such that the seal may be disposed about the plurality of droplet ejection orifices. This droplet ejection orifice cover may be interconnected with the inhaler housing by a tether, although other ways may be utilized for storing the droplet ejection orifice cover when not in use.
All of the various other features addressed above in relation to the first aspect of the present invention may be used individually and/or in any combination in relation to this second aspect of the present invention as well.
A third aspect of the present invention is an inhaler which includes a plenum with an air inlet port. An airflow conduit is fluidly interconnected with this plenum and includes a pair of longitudinally spaced ends. One of these ends interfaces with the plenum, while its opposite end interfaces with a mouthpiece. There is an offset between the air inlet port on the plenum and the end of the airflow conduit which interfaces with the plenum. A droplet ejection device is at least fluidly interconnectable with the airflow conduit. Medicament droplets which are entrained in the airflow through the airflow conduit, from the plenum, are directed into a mouth of a user of the inhaler through the mouthpiece.
All of the various other features addressed above in relation to the first aspect of the present invention may be used individually and/or in any combination in relation to this second aspect of the present invention as well.